Electric heater



Nov. 26, 1935. J. F; BALL ELECTRIC HEATER Filed Sept. 18, 1929 ATTORNEYS.

Patented Nov. 26, 1935 UNITED STATES PATENT OFFICE ELECTRIC HEATER Joseph Franklin Ball, San Francisco, Calif.

Application September 18, 1929, Serial N 0. 393,466

3 Claims.

My present invention relates to electric heaters and more particularly to a new and novel type of heater by means of which the combined efiect of current flowing through the resistance and current induced in adjacent conducting members is applied to the heating or a circulating medium.

One object of my invention is to provide a new, novel and elfective type of heater unit for use in heating a circulating medium.

Another object of my invention is to provide in an electric heater unit a new and novel arrangement, whereby when alternating currents are available to energize the resistance element of my improved heater, adjacent parts thereof will be in inductive relation therewith and, as a result, afford a path for induced currents which will co-operate with the resistance winding to facilitate a rapid heating of the medium being circulated through the heater.

My invention also possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description, where I shall outline in full that form of my invention which I have selected for illustration in the drawing accompanying and forming a part of this specification. In the drawing, I have shown three forms of heaters embodying my invention, but it is to be understood that I do not limit myself to such forms, since the invention, as set forth in the claims, may be embodied in a plurality of other forms.

In the drawing:-

Fig. 1 is a vertical elevation showing my improved heater inserted in the flue of an ordinary hot air furnace,

Fig. 2 is a sectional view of one form of my invention,

Fig. 3 is a sectional view projected from the unit illustrated in Fig. 2.

Fig. 4 is a sectional view of a modified form of my invention,

Fig. 5 is a sectional view projected from the unit illustrated in Fig. 4, and

Fig. 6 is a sectional view showing an embodiment of my invention which is particularly adapted to the heating of water and other fluids.

In Fig. 1 of the drawing, III designates an ordinary hot air furnace having the usual outlet fiues II. Inserted in the flues II, I show a length of pipe I2 in which there is disposed a resistance heater unit I3. This heater unit I3 is wound upon a metallic cylindrical core I4 and. in inductive relation therewith, so that, when energized, currents will be induced into the cylindrical member I4 and thus eifect a more rapid heating of the air circulating therethrough than would be the case were the heater unit I3 alone relied upon.

By referring now to Fig. 2, it will be seen that 5 the length of pipe I2 is flanged at the ends so that it may be inserted in any standard flue and that the cylindrical support I4 is mounted centrally thereof. Surrounding the cylindrical member I4, I show a suitable insulation I5, upon which the resistance winding I3 is wound. The cylindrical support It is shown as held in position upon suitable radially extending stays I6. Interposed between the winding I3 and the pipe I2, I show a second cylindrical member II. member I! completely surrounds the resistance unit I3 and is spaced a distance therefrom so that air may freely circulate over the resistance unit I3 along the interior thereof and also around its outer surface. With this arrangement it will 20 be seen that there is provided a restricted passageway for the air over the resistance unit. It will also be understood that because of the inductive relation of this cylindrical member II it will prevent any magnetic lines cutting the outer 35 pipe I2 and, as a result, prevent the induction of currents in the latter. With this arrangement, it will be seen that the air has three possible paths through the section of pipe I2, one path being through the center of the cylindrical pipe I4; another path immediately outside thereof and inside of the cylindrical member II; and a third path outside of the cylindrical member II.

In Figs. 4 and 5 it will be noted that, instead of permitting the air to flow freely over the resistance unit I3, I have provided a plurality of radially disposed paths for the medium to be heated, these paths being formed by suitable conduits I8 which are arranged in spaced relation about the heater unit I3 and within the cylindrical shell II. With this arrangement, it will be seen that the heater unit I3 will first heat up the stationary air immediately surrounding it and that this heat so accumulated will then be transferred to the air which circulates through the conduits I8 and through the center of the support I4 upon which the resistance unit I3 is wound. With this unit it will be seen that the flow of the medium to be heated is somewhat restricted and, as a result, a greater degree of heat will be possible of attainment with this type of heater, this being particularly true where a lesser circulation of air is required.

The embodiments of my invention above described. it will be understood, will have their This cylindrical 15 most frequent application in connection with the so-called hot air systems of heating, but it should be understood that they may be equally applicable to the heating of mediums other than air.

For the purpose of applying the principles of my invention to the heating. of water or the generation of steam, I propose to embody my invention in the form illustrated in Fig. 6 of the drawing. In this embodiment, the cylindrical supporting member I4 is shown as a length of pipe through which the fluid to be heated may freely circulate. This pipe, it will be understood, is in inductive relation with the resistance unit [3 so that currents will be induced therein when the winding I3 is energized by alternating current. Immediately surrounding the resistance winding 13, I show a cylindrical housing I9 which is closed at one end, as by the member 20, so that when the member is screwed into a liquid container, as by the plug or pipe fitting 2|, it will prevent the escape of any fluid into which the heater unit is submerged.

In operation, it is contemplated that a unit of this character will be mounted in the lower portion of a container and below the level of the liquid therein and that the liquid will be free to enter the inner end of the cylindrical support 14 and flow outwardly therethrough and up to a point where it will return to the container.

While I have, for the sake of clearness and in order to disclose my invention so that the same can be readily understood, described and illustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the specific means disclosed but may be embodied in other ways that will suggest themselves, in view of this broad disclosure, to persons skilled in the art. It is believed that this invention is broadly new and it is desired to claim it as such so that all such changes as come Within the scope of the appended claims are to be considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. In an electric heater, the combination of a metallic cylindrical housing through which a medium to be heated may pass, a cylindrical support having a passageway therethrough disposed axially in said housing, an alternating current resistance winding wound upon said cylindrical support, and a plurality of tubes adjacent said winding and said first cylindrical housing adapted to define restricted passageways for the medium to be heated.

2. A heater of the character described which comprises in combination, a cylindrical housing, a helically wound heating unit arranged concentrically of the housing, a tubular passage arranged concentrically of said heating unit, a plurality of tubular passages arranged parallel to and closely adjacent said heating unit, and means for directing fluid flowing through said housing to said tubular passages whereby said fluid will be in close proximity to said heating unit.

3. In a heater of the character described, a section of pipe of relatively small diameter, a heating element wound on and insulated from said section of pipe, a second section of pipe of slightly larger diameter than the first named section concentrically surrounding the same and having its inner wall spaced from said heating element, means closing one end of the larger section and sealing it to the outer periphery of the smaller section adjacent an end thereof, the other end of the larger section being open for the passage of current conductors to the heating element, a threaded fitting surrounding and secured to the larger section at its open end whereby it may be inserted into and connected with a container for liquid to be heated, the corresponding end of the smaller section being adapted for communication with said container whereby liquid in the container will be caused to circulate through the smaller section and around the exterior of the larger section.

JOSEPH FRANKLIN BALL. 

